Re: RFP: Recursive query in 8.4

> On Tue, Feb 19, 2008 at 3:36 AM, Tatsuo Ishii <ishii@postgresql.org> wrote:
> >  We propose to implement the recursive query (WITH RECURSIVE clause)
> >  defined in SQL:1999 and later. With the recursive query, one can
> >  easily inquire the data expressed as tree and graph structures.  The
> >  actual syntax we prefer is the one defined in SQL:2008 (it's not
> >  published yet, but I have a closest draft).
> 
> I am sure you are aware of various ad hoc approaches that are
> currently possible.  The recursive clause seems to generalize these
> approaches.
> 
> Do you expect that your proposed solution will have performance
> advantages over solutions like using recursive functions and (for tree
> organized data) arrays?

I hope so. But the first thing I would like to do is, to implement the
right thing (i.e. following the standard).

I don't see any reason that the proposal gets less performance than
existing functions.  Moreover the proposal could better cooperate with
the optimizer since it can feed more info to it. Any ideas to enhance
the performance are welcome.
--
Tatsuo Ishii
SRA OSS, Inc. Japan